1. Field of the Invention
The present invention relates to a backlash prevention mechanism of an adapter for an optical connector in high-density mounting of an optical connector plug.
2. Description of the Conventional Art
Conventionally, a so-called snap-in system has been employed as a backlash prevention mechanism of an adapter for an optical connector which is used in high-density mounting of an optical connector plug. As shown in FIGS. 7A and 7B, the so-called snap-in system is provided with locking protrusions 11a and 11b which are formed in a side surface of an adapter main body 10 for an optical connector, and spring locking pieces 40a and 40b for fixing a panel, the spring locking pieces 40a and 40b being formed so as to face to the locking protrusions 11a and 11b, is inserted to an adapter attaching hole Q of a panel P while pressing the spring locking pieces 40a and 40b, and is fixed by pinching an opening edge portion of the adapter attaching hole Q between the locking protrusions 11a and 11b and the spring locking pieces 40a and 40b. 
In the meantime, in the case of the snap-in system mentioned above, a gap is generated between an opening edge inner side of the adapter attaching hole Q pinched by the locking protrusions 11a and 11b and the spring locking pieces 40a and 40b, and the adapter main body 10, when the adapter main body 10 for the optical connector is inserted to the adapter attaching hole Q of the panel P. As a result, there has been a problem that backlash is generated in vertical and lateral directions in the adapter main body 10.
Further, in the case that the panel P is vibrated, there has been a problem that chattering sound is generated by the backlash of the adapter main body 10 as mentioned above.
Accordingly, the applicant of the present invention has proposed a backlash prevention mechanism of an adapter for an optical connector (patent document 1), the backlash prevention mechanism being provided with a backlash prevention tool 100 which is attached to an adapter main body for the optical connector and is formed into a C-shaped frame shape.
Namely, the backlash prevention tool 100 is provided with first locking piece portions 300a and 300b which are formed into a C-shaped frame installed to the adapter main body 10 for the optical connector, and are folded in a diagonally outward direction so that both left and right end side surface portions of the C-shaped from come into pressure contact with the opening edge inner sides of the adapter attaching hole Q of the panel P in a lateral direction, and second locking piece portions 400a and 400b which are cut and raised from the center of both the left and right end side surface portions of the C-shaped frame so as to face to the locking protrusions 11a and 11b which are formed in both the left and right side surface portions of the adapter main body 10, as shown in FIGS. 8A and 8B.
As mentioned above, the adapter main body 10 is inserted to the adapter attaching hole Q while pressing the second locking piece portions 400a and 400b of the backlash prevention tool 100, and pinches and fixes both the left and right side portions of the opening edge portion of the adapter attaching hole Q between the locking protrusions 11a and 11b and the second locking piece portions 400a and 400b, and the first locking piece portions 300a and 300b of the backlash prevention tool 100 are formed so as to be pressure crushed and come into pressure contact with the opening edge inner side of the adapter attaching hole Q.